Insulating link for pull chains



July 1, 1930.

W. C. TREGONING lNSULATING LINK FOR PULL CHAINS Filed March 3, 1927 l IINfENTOR. wiwl ATTORNEY.

Patented July 1, 1930 entree s'rares PATENT orrica WILLIAM C. TREGONING,OF MILWAUKEE, WISCONSIN, ASSIGNOR, BY MESNE AS- SIGNMENTS, T0CUTLER-HAMMER, INCL, TION OF DELAWARE INSULATING LINK Application filedMarch 3,

This invention relates to improvements in insulating links for switchpull chains.

An object of the invention is to provide an insulating link of the abovecharacter which is of improved and simplified constrpction, embodyingbut one piece of materia Another object is to provide for engagement andretention of the metallic links of the chain by the insulating linkitself, whereby the necessity for the usual metallic attachments for thelatter is obviated.

Another object is to provide insulating links of similar character whichare respectively adaptable for either ermanent or manual attachment to apull c liLlIl.

Another object is to provide an insulating link which may be readily andeconomically manufactured.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawing illustrates certain embodiments of my inventionwhich will now be described, it being understood that the inventionsusceptible of embodiment in other forms without departing from thespirit and scope of the appended claims. In the drawing, Figures 1 and 2are on larged views in front elevation and longitudinal section,respectively, of one form of insulating link constructed in accordancewith my invention, and showin the same applied to a well knowntype ofead chain. Figs. 3 and 4 are front elevational and longitudinalsectional views, respectively, of a modified form of the deviceillustrated in Fi s. 1 and 2.

igs. 5 and 6 are front elevational and longitudinal sectional views ofanother form of insulating link constructed in accordance with myinvention, and

Figs. 7 and 8 are front elevational and longitudinal sectional views,respectively, of a modified form of the device illustrated in Figs. 5and 6.

Referring to the drawing, wherein like parts have been given likecharacters of reference, the numeral 10 designates a tubular memberformed of tough and relatively stifl insulating material which iscapable of OLE MILWAUKEE, WISCONSIN, A CORPORA- FOR PULL CHAINS 1927.Serial No. 172,547.

being deformed or bent under pressure and of retaining therein suchdeformations. Thus, as shown in Figs 1 and 2 the tubular member 10 hasan inside diameter sufficiently large to permit insertion into itsopposite ends of one or more beads or balls 11 of a pull chain. Afterinsertion of the respective terminal or end beads 11, as shown in dottedlines in Fig. 1, the wall of member 10 is indented or pressed inwardlyas shown at 12 to provide internal shoulders or shutments 12", whichprevent withdrawal of said beads 11 from the insulating member or link10. While I have shown such abutments as formed by two circumferentiallyspaced indentations in the wall of member 10 at each end thereof, it isobvious that the number of indentations may be varied; whereas ifdesired such retaining means may take the form of a complete annularinden tation adjacent to or at the respective ends of member 10.

Thus as shown in Figs. 5 and 6 the terminal beads 11 of the two portionsof the pull chain to be insulated from each other are inserted into therespective ends of tubular member 10, whereupon the ends of the latterare spun or pressed inwardly to provide annular retaining shoulders 13.

As will be apparent the insulating links shown in Figs. 1, 2, 5 and 6are especially adapted for application to a pull chain dur ingmanufacture or assembly of the latter. On the other hand, the insulatinglink illustrated in Figs. 3 and 4 is particularly adapted forapplication to a pull chain after complete assembly of the latter; thatis to say, as an attachment to be applied by the user. The tubularmember 10 in Figs. 3 and 4 is in many respects like that shown in Figs.1 and 2, being provided with the indentations 12 forming shoulders orabutinents 12 for retaining the beads 11 within the ends thereof.However, in order to provide for manual insertion of the terminal beads11 within the respective ends of tubular member 10 the latter is slitlongitudinally, as indicated at 14', whereby pressure manually exertedupon said terminal beads 11 will cause expansion of member 10 to adegree suiiicient to permit passage of said beads over and intointerlocking engagement with the internal shoulders or abutments 1Q.\Vhile I have shown a single slit ll extending throughout the length ofmember 10, it will be apparent that the latter may alter natively beprovided with one or more relatively s .orter slits extending inwardlyfrom each end thereof for the purpose aforementioned. l'loreover. inorder to prevent accidental insertion of such a number of beads withinthe respective ends of the tubular member 10 to result in too closeproxim ity of the respective chain ends, I preferably provide a pair oflon itudinally spaced indentations forming abntments or shoulders asindicated at 15.

The insulating link shown in Figs. 7 and 8 is likewise apt-ed for manualattachment to the en' 'r of separated portions of a pull chain. Thisdevice is in general like that shown in Figs. 5 and 6, in that therespective ends ot the tubular member 10 are spun or pressed inwardly toprovide the annular retaining shoulders 13. Moreover. the member 10 slitor slotted longitudinally thereof as indicated at 15, and as describedin connection with Figs. 3 and 4.. The slit 1? is provided with anintermediate enlargement 16. oi a size sui'licient to permit insertionof the respective terminal beads 11 whereby the latter may be movedlongitudinally and internally of the member 10 to its opposite ends.

The insulating material of which the tubular members 10 are formed maycomprise bakelite or any other insulating substance having thecharacteristics aforementioned, whereas the substance employed maypreferably include a fibrous filler to increase the toughness andresiliency thereof.

In the foregoing manner I have provided a pull chain insulating linkwhich is neat and attractive in appearance, and which may be readily andcheaply manufactured from a single piece of tubular insulating stock.

\Vhat I claim as new and desire to secure by Letters Patent is:

1. An insulator for head chains comprising a tubular insulating member,said mem her being slit longitudinally to permit expansion ot the wallsthereof, integral internal projections adjacent to the respective endsof said member, said projections having surfaces converging toward eachother inwardly of said ends to facilitate passage of chain beadstherebeyond, and said pro jections also having transverse shoulders toresist removal of the chain beads from said member.

2. An insulator for bead chains comprising a tubular insulating member,said mem her being slit longitudinally to permit expansion of the wallsthereof, integral intera us nal projections adjacent to the respectiveends of said member, said projections being arranged to provide agradually restricted passage inwardly of said respective ends tonecessitate forcible endwise insertion of the chain beads thereinto saidprojections also having transverse shoulders to resist removal of thechain beads from said member, and internal abutments locatedintermediate the ends of said member, said abutments being formed bydepressing the walls of said memher and being adapted to limit thenumber oi beads insertable within the respective ends of said member.

In witness whereof, I have hereunto subscribed my name.

IVILLIAM C. TREGONING.

